Gaseous electric discharge lamp device



Dec. 21, 1937. R, ROMPE ET AL 2,103,041

GASEOUS ELECTRIC DISCHARGE LAMP DEVICE Filed Aug. 21,1936

INVENTORS Robe r'b R om pe Wolf an Thour 1.

RNEY

Patented Dec. 21, 1937 UNITED STATES.

PATENT OFFICE 2,103,041 GASEOUS .Emc'rm c DISCHARGE LAMP DEVICE Robert Rompe, Berlin, and Wolfgang Thouret,

Bcrlin-Wilmersdorf, Germany,

assignors to General Electric Company, a corporation of New York Application August 21, 1936, Serial No. 97,278

In Germany August 28, 1935 4 Claims.

](L mospheres are now known in the art. The containers of such devices are in the nature of capillary tubes and have an electrode comprising an electron emitting oxide material mounted at each end thereof which electrodes are separated a greater distance than the inner diameter of the tubular container.

The object of the present invention is to provide a vapor electric arc discharge lamp device of simple structure, capable ofoperating with a vapor pressure greater than 20 atmospheres and which has a long useful operating life. Another object of the invention is to provide a vapor lamp useful as a light source in picture projecting apparatus. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

In accordance with these objects the high pressure vapor lamp of the present invention comprises a spherical, or approximately spherical container of vitreous material, such as quartz, having a diameter of approximately 20 to mm.

" and having electrodes mounted in said container terial are thus deposited on the walls of the apthey are deposited. Preferably the diameter of the appendage is greater than the distance between the most remote parts of the electrodes. The sputtered particles of the electrode mapendage rather than on the walls of the container through which the light is transmitted. The appendage is provided with a heat conservator, such as a mirror coating, to reduce the heat losses by radiation therefrom and thus to prevent the condensation of mercury vapor therein during the operation of the device. The close spacing of picture projecting apparatus and makes possible the starting and operation of the lamp without the use of a high voltage transformer and on line voltages of approximately 220 v. When desired. a small quantity of electron emitting oxide, such as an alkaline earth oxide, is incorporated in the electrodes, but preferably the electrodes consist of tungsten.

In the drawing accompanying and forming part of this specification two embodiments of the invention are shown in which Fig. 1 is a side elevational, partly sectional view of one embodiment of the invention, and

Fig. 2 is a front elevational, partly sectional view of another embodiment of the invention.

Like numbers denote like parts in both the figures.

Referring to Fig. 1 of the drawing a gaseous electric discharge device comprises an approximately spherical container I made of a vitreous material, such as quartz. The diameter of said container I is approximately 30 mm. Said container I has two solid electrodes I mounted at equal distances from the center of said container I, which electrodes 2 are separateda distance of about 3mm. The electrodes 2 consist of a high melting point metal, such as tungsten, and, when desired, have a small quantity of an electron emitting material, such as an alkaline earth oxide, incorporated therein. The electrodes 2 are supported by the current leads 3 which are hermetically sealed into the tubular appendages l of the.

container I. Said container I has therein a'start ing gas, such as neon, at a pressure of approximately 5 mm. and a small quantity of vaporizable material 5, such as mercury, which can be device. -Said container I has a domelike, protruding appendage 6 which has a diameter greater than the distance between the remote back surfaces of the electrodes 2. During the operation of the device the sputtered material from the electrodes! is carried up into the appendage 6 in the direction indicated by the dotted arrows in the drawing by the convection currents caused by the heat from the luminous arc discharge between said electrodes 2. The sputtered electrode particles are deposited on the walls of the appendage 6 or if such deposition does not take place on the walls of the appendage 6 the sputtered particles fall to the bottom of the spherical container. I. The side walls of th'e'container I. are

thus free from light absorbing deposits of sputtered electrode material..

completely vaporized during the operation of the I the electrodes facilitates the use of the device in when desired, a wall 8 is interposed between the electrodes 2 and the part i of the container i, as illustrated in Fig. 2 of the drawing. The wall 8 has a perforation Ill therein directly in line with the discharge path between said electrodes 2 and said wall 8 extendsfrom the appendage 6 to the bottom 9 of the spherical container I. The wall 8 serves as an additional guiding and depositing surface for the sputtered particles of electrode material which are not deposited on the walls of the appendage 6. The light emitted by the arc discharge passes unobstructed through the perforation l0 and thrgugh the part I of the container I.

When desired, the appendage 6 is provided with a cylindrical skirt extending into the container i and terminating just above the electrodes 2. The skirt has approximately the same diameter as said appendage 6. This skirt serves the same purpose as the wall 8. When desired, the appendage 6 is provided with 'a mirror coating l2, such as a silver coating, which radiates the heat emitted by the discharge back into the lamp to maintain the appendage 6 at a higher temperature than the condensation temperature of the mercury vapor during the operation of the device. The seals 4 and seal-off tip l3 of the container I are also provided with a similar reflecting coating M or IE for the same purpose, when desired. When the light emission is desired in only one direction the entire container l is completely coated with a similar heat reflecting coating with the exception of a small opening in the direction in which light emission is desired.

While we have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention, for example, a heat insulating material, such as asbestos, is used in place of the mirror coating, when desired.

What we claim as new and desire to secure by Letters Patent of the United States, is:-

1. A gaseous electric discharge lamp device comprising a spherical container, a gaseous atmosphere therein, electrodes and electrode leads sealed therein, said electrodes being separated a distance less than the diameter of said container and being mounted adjacent the center of said container, said electrode leads being substantially in line and being fused into opposite parts of said container, and a dome-like, protruding appendage in the wall of said container above said electrodes, the axis of said appendage being substantially normal to said electrode leads and the discharge path between said electrodes to prevent the formation of light absorbing electrically conducting deposits of sputtered electrode material at other parts of said container.

, 2. Agaseous electric discharge lamp device comprisinga spherical container,agaseous atmosphere therein, electrodes and electrode leads sealed therein, said electrodes being separated a distance less than the diameter of said container and being mounted adjacent the center of said container, said electrode leads being substantially in line and being fused into opposite parts of said container, and a dome-like, protruding appendage in the wall of said container above said electrodes, the diameter of said appendage being greater than the distance between the remote surfaces of said electrodes, the axis of said appendage being substantially normal to said electrode leads and the discharge path between said electrodes to prevent the formation of light absorbing, electrically conducting deposits of sputtered electrode material at other parts of said container.

3. A gaseous electric discharge lamp device comprising a spherical container, a gaseous atmosphere therein, electrodes and electrode leads sealed therein, 'said electrodes being separated a distance less than the diameter of said container and being mounted adjacent the center of said container, said electrode leads being substantially in line and being fused into opposite parts of said container, 2. dome-like, protruding appendage in the wall of said container above said electrodes, the axis of said appendage being substantially normal to said electrode leads and the discharge path between said electrodes, the diameter of said appendage being greater than the distance between the remote surfaces of said electrodes and a cylindrical wall having the same diameter as said appendage extending from said appendage and terminating just above said electrodes, the axis of said wall and said appendage being normal to said electrode leads and the discharge path between said electrodes to prevent the formation of light absorbing, electrically conducting deposits of sputtered electrode material at other parts of said container.

4. A gaseous electric discharge lamp device comprising a spherical container, a gaseous atmosphere therein, electrodes sealed therein, said electrodes being separated a distance less than the diameter of said container and being mounted adjacent the center of said container, a dome-like protruding appendage in the wall of said container above said electrodes and a perforated wall extending from said appendage to the bottom of said container and interposed between said electrodes and the wall of said container to prevent the formation of light absorbing deposits of sputtered electrode material at other parts of said container. I

ROBERT ROMPE. WOLFGANG THOURET. 

